Temporal-spatial variations of Plio-Pleistocene volcanic activity in the Ryohaku Mountains, central Japan : evidences from K-Ar ages.
-
- TANASE Atsushi
- Sumiko Consultants Co. LTD.
-
- OIKAWA Teruki
- Institute of Geology and Geoinformation, Geological Survey of Japan, AIST
-
- NINOMIYA Atusi
- Sumiko Consultants Co. LTD.:(Present office)Japan Atomic Energy Agency
-
- HAYASHI Shintaro
- Faculty of Education and Human Studies, Akita University
-
- UMEDA Koji
- Japan Atomic Energy Agency
Bibliographic Information
- Other Title
-
- K-Ar年代測定に基づく両白山地の鮮新 : 更新世火山活動の時空分布
- K Ar ネンダイ ソクテイ ニ モトズク リョウハク サンチ ノ センシン コウシンセイ カザン カツドウ ノ ジクウ ブンプ
Search this article
Abstract
Temporal and spatial variations in Plio-Pleistocene volcanism in the Ryohaku Mountains, central Japan, have been investigated by newly obtained K-Ar ages on 38 groundmass samples separated from volcanic rocks. The obtained groundmass ages show small variations and errors and are relatively younger than K-Ar ages from bulk rocks reported by previous studies indicating lesser effect of excess argon from phenocrysts. Based on the newly obtained ages and volcano stratigraphic data, we identify activity periods of 1.0-0.8 Ma for Kyogatake Volcano, 0.8-0.7 Ma for Hoonji Volcano, 1.0-0.8 Ma for Toritateyama Volcano, 0.8 Ma for Akausagiyama Volcano, 3.1-2.9 Ma and 2.5 Ma for Gankyoji-Sannomine Volcano, 1.5 Ma for Choshigamine Volcano, 0.3 Ma for Bishamon Volcano, and 1.2 to 1.1Ma for Eboshi-Washigatake Volcano. The volcanoes in the Ryohaku Mountains form two volcanic rows of the Kuzuryu and Hakusan Volcanic Chains which have ESE-WNW and N-S alignments, respectively. Early volcanic activity occurred intermittently from 3.6 Ma to 1.5 Ma, and the volcanoes near the junction of the two volcanic chains were active. The volcanic activity in the ESE-WNW trending Kuzuryu Volcanic Chain was restricted in the age range from 1.2 Ma to 0.7 Ma with migration from Eboshi-Washigatake Volcano (ESE end) to Hoonji Volcano (WNW end). The N-S trending Hakusan Volcanic Chain was active from 0.4 Ma to the present.
Journal
-
- BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN
-
BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN 52 (1), 39-61, 2007
The Volcanological Society of Japan
- Tweet
Details 詳細情報について
-
- CRID
- 1390282679281725440
-
- NII Article ID
- 110006240393
-
- NII Book ID
- AN10512786
-
- ISSN
- 21897182
- 04534360
-
- NDL BIB ID
- 8745835
-
- Text Lang
- ja
-
- Data Source
-
- JaLC
- NDL
- CiNii Articles
-
- Abstract License Flag
- Disallowed